The economy may be chugging along, but many Americans are still struggling to afford a basic middle class life.

Nearly 51 million households don't earn enough to afford a monthly budget that includes housing, food, child care, health care, transportation and a cell phone, according to a study released Thursday by the United Way ALICE Project. That's 43% of households in the United States.

The figure includes the 16.1 million households living in poverty, as well as the 34.7 million families that the United Way has dubbed ALICE -- Asset Limited, Income Constrained, Employed. This group makes less than what's needed "to survive in the modern economy."

"Despite seemingly positive economic signs, the ALICE data shows that financial hardship is still a pervasive problem," said Stephanie Hoopes, the project's director.

California, New Mexico and Hawaii have the largest share of struggling families, at 49% each. North Dakota has the lowest at 32%.

Many of these folks are the nation's child care workers, home health aides, office assistants and store clerks, who work low-paying jobs and have little savings, the study noted. Some 66% of jobs in the US pay less than $20 an hour.

The study also drilled down to the county level.

For instance, in Seattle's King County, the annual household survival budget for a family of four (including one infant and one preschooler) in 2016 was nearly $85,000. This would require an hourly wage of $42.46. But in Washington State, only 14% of jobs pay more than $40 an hour.

Seattle's City Council just passed a controversial tax on big businesses to help alleviate the city's growing homelessness and affordable housing problems.